The major objective of the proposed project is to investigate the morphological, cytochemical and hormonal basis for cataract induction. Specific aims will be to study the mechanism(s) of initiation, progression and reversal of galactose cataracts. Light, transmission and scanning electron microscopic techniques will be used to systematically analyze galactose induced alterations in rat lenses. The effect of galactose feeding on lenses of young adult rats, and on fetal lenses through cross-placental transport of galactose to fetuses will be investigated. Reversibility of galactose induced lesions will be studied. Hormonal regulation and control, if any, on cataract induction and reversal is proposed to evaluated. During the process of cataractogenesis and reversal two key enzymes, Na-K-ATPase and acid phosphatase, will be localized and studied at light and electron microscopic level. Lenses and plasma from animals subjected to different experimental conditions will be analyzed for hexoses and polyol levels using gas liquid chromatography (GLC). Results obtained from the proposed study will be of considerable importance to biomedical sciences in general and will be of great significance in the field of ophthalmology in particular. Abnormal carbohydrate metabolism, particularly in diabetic conditions, is known to be the primary cause of a large percentage of cataract formtion and blindness. It is therefore felt that the experiments proposed are of immense importance in the field of ophthalmology and the long term goal of this project is to find ways of preventing or reversing sugar cataracts. The proposed project will allow us to understand the mechanism(s) of sugar cataract formation and regression. Moreover, these studies will elucidate the factor(s) responsible for the restoration of tissue transparency.